1. Technical Field
The present invention relates to a magnetic head for recording or reproducing information signals from a magnetic disk. The present invention also relates to a magnetic disk drive having such a magnetic head.
2. Prior Art
Conventionally, a removable disk recording media is proposed to be a large-capacity magnetic disk or floppy disk having several tens or hundreds of megabytes of storage space. Providing a large-capacity removable magnetic disk requires accumulation of various technologies such as recording media materials, structures of magnetic head elements (head chips), reproduction signal processing, the use of tracking servo, and the like.
A so-called floating-type magnetic head is proposed to be provided on a magnetic disk drive which records or reproduces information signal using a large-capacity magnetic disk. The floating magnetic head slightly floats over the recording surface of a fast rotating magnetic disk for recording and reproducing data.
The floating magnetic head comprises a magnetic head element and a slider in which the magnetic head element is embedded. As shown in FIG. 4, the magnetic head is supported by a suspension arm 109. When a magnetic disk 101 fast rotates in the direction of the arrow r in FIG. 4, an air stream occurs and applies a pressure to a slider 103 to float the magnetic disk 101. Floating over the magnetic disk 101, the magnetic head writes or reads information signals from the magnetic disk 101.
For the above-mentioned magnetic head, the slider needs to stably float over the magnetic disk. For this purpose, as shown in FIG. 1, the slider 103 is provided with a pair of rails 104 on an opposite surface thereof facing against the signal recording surface of the magnetic disk. These rails 104 are parallel to the tangential direction of a recording track on the signal recording surface. Tapered ramp edges 105 are formed so as to leave from the signal recording surface at front ends of these rails 104 in the relative movement direction against the signal recording surface. These ramp edges 105 let an air stream generated by magnetic disk rotation stably flow between the magnetic disk and the slider. A magnetic head element 106 is embedded in the rail 104 at a rear end of the slider 103.
As shown in FIG. 2, each side edge of the rail 104 is polished by means of blending to form a chamfer 107 on the slider 103. If no polishing is applied, the slider edged will form a sharp ridge. The ridge may damage a magnetic disk. Alternatively, the ridge or its vicinity may break to generate dust.
As shown in FIG. 3, the slider is worn by contacting or sliding touchingly on a large-capacity magnetic disk when recording or reproducing information signals. Especially, an abrasion occurs near ridges between rear ends of the ramp edges 105 and principal planes of the rails 104 or at rear sides thereof. Such an abrasion may form a wear portion outside ridges between rear ends of the ramp edges 105 and principal planes of the rails 104.
When such an abrasion deforms the slider, an accurate positional relationship cannot be maintained between the magnetic head element 106 and the magnetic disk, disallowing proper recording or reproducing information signals on the magnetic disk. Dust particles generated by the abrasion may be accumulated on the slider surface to damage the magnetic disk or magnetic head element. Such dust particles may increase a friction between the slider and the magnetic disk or damage the magnetic disk. Further, this may increase a load on a motor which rotates the magnetic disk, thus shortening the motor life or increasing the overall power consumption.
It is therefore an object of the present invention to provide a magnetic head which can sufficiently suppress slider abrasion, prevent the generation of dust due to the abrasion, and permit satisfactory recording and reproduction of information signals on the magnetic disk. It is another object of the present invention to provide a manufacturing method of such a magnetic head and a magnetic disk drive having such a magnetic head.
A magnetic head according to this invention, comprising: a slider having an opposite surface against a signal recording surface on a rotated magnetic disk; a pair of parallel rails protuberantly provided on this opposite surface in parallel with a tangential direction of a recording track on said signal recording surface; a tapered ramp edge on each of these rails at a front end edge in a relative movement direction with a slant leaving from said signal recording surface; and a magnetic head element provided on said slider""s rail, wherein: said slider is provided with a chamfer formed by means of polishing between a rear end of said ramp edge and a front end edge of said rail""s principal plane.
A manufacturing method of a magnetic head according to this invention, wherein said magnetic head comprising a slider having an opposite surface against a signal recording surface on a rotated magnetic disk, a pair of parallel rails protuberantly provided on this opposite surface in parallel with a tangential direction of a recording track on said signal recording surface, a tapered ramp edge on each of these rails at a front end edge in a relative movement direction with a slant leaving from said signal recording surface, and a magnetic head element provided on this slider""s rail, wherein: polishing is applied to form a chamfer at a ridge formed between a rear end of said ramp edge on said slider and a front edge of a principal plane on said rail and each rail""s side edge is also polished to form a chamfer; and said chamfer at a front end of said rail in a relative movement direction against a signal recording surface is made wider than said chamfer at a rear end in said relative movement direction.
A magnetic disk drive according to this invention, comprising: a rotating mechanism for rotating a magnetic disk; and a head support mechanism for supporting a magnetic head to be faced against a signal recording surface of a magnetic disk rotated by said rotating mechanism; wherein said magnetic head comprises an opposite surface against a signal recording surface of said magnetic disk, a pair of parallel rails protuberantly provided on this opposite surface in parallel with a tangential direction of a recording track on said signal recording surface, a slider having a tapered ramp edge formed on each of these rails at a front end in a relative movement direction with a slant leaving from said signal recording surface, and a magnetic head element provided on this slider""s rail, wherein said slider is provided with a chamfer formed by means of polishing between a rear end of said ramp edge and a front end of said rail""s principal plane.
As mentioned above, a magnetic head according to the present invention is provided with a slider which has a chamfer formed between a rear end of a ramp edge and a front end edge of a rail""s principal plane.
A manufacturing method of the magnetic head according to the present invention forms a chamfer by polishing a ridge formed between the rear end of the slider""s ramp edge and the front end edge of the rail""s principal plane. In addition, a chamfer is formed by polishing each rail""s side edge. With reference to a signal recording surface, the chamfer at the front end side of each rail in the relative movement direction is made wider than a flat face at the rear end side thereof in the same direction. A magnetic head of the magnetic disk drive according to the present invention comprises a slider having a chamfer formed between the rear end of the slider""s ramp edge and the front end edge of the rail""s principal plane.
Namely, even when a large-capacity magnetic disk is used, the present invention can provide a magnetic head which can sufficiently suppress slider abrasion, prevent the generation of dust due to the abrasion, and permit satisfactory recording and reproduction of information signals on the magnetic disk. The present invention can also provide a manufacturing method of such a magnetic head and a magnetic disk drive having such a magnetic head.